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<li class="navelem"><a class="el" href="namespacefaiss.html">faiss</a></li><li class="navelem"><a class="el" href="structfaiss_1_1RandomGenerator.html">RandomGenerator</a></li>  </ul>
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<p>random generator that can be used in multithreaded contexts  
 <a href="structfaiss_1_1RandomGenerator.html#details">More...</a></p>

<p><code>#include &lt;<a class="el" href="utils_8h_source.html">utils.h</a>&gt;</code></p>
<table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="pub-methods"></a>
Public Member Functions</h2></td></tr>
<tr class="memitem:a583f124ecacdbe037ac96e23a44dd420"><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a583f124ecacdbe037ac96e23a44dd420"></a>
int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structfaiss_1_1RandomGenerator.html#a583f124ecacdbe037ac96e23a44dd420">rand_int</a> ()</td></tr>
<tr class="memdesc:a583f124ecacdbe037ac96e23a44dd420"><td class="mdescLeft">&#160;</td><td class="mdescRight">random 31-bit positive integer <br/></td></tr>
<tr class="separator:a583f124ecacdbe037ac96e23a44dd420"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:acbceaa8b017793ca4f8d90e644b0d7f4"><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="acbceaa8b017793ca4f8d90e644b0d7f4"></a>
long&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structfaiss_1_1RandomGenerator.html#acbceaa8b017793ca4f8d90e644b0d7f4">rand_long</a> ()</td></tr>
<tr class="memdesc:acbceaa8b017793ca4f8d90e644b0d7f4"><td class="mdescLeft">&#160;</td><td class="mdescRight">random long &lt; 2 ^ 62 <br/></td></tr>
<tr class="separator:acbceaa8b017793ca4f8d90e644b0d7f4"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:aa460b9bac2593cd1d71305e10ab51af6"><td class="memItemLeft" align="right" valign="top">int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structfaiss_1_1RandomGenerator.html#aa460b9bac2593cd1d71305e10ab51af6">rand_int</a> (int max)</td></tr>
<tr class="memdesc:aa460b9bac2593cd1d71305e10ab51af6"><td class="mdescLeft">&#160;</td><td class="mdescRight">generate random number between 0 and max-1  <a href="#aa460b9bac2593cd1d71305e10ab51af6">More...</a><br/></td></tr>
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<tr class="memitem:ac82a433d7bfa56d750907ba5cf74aed7"><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="ac82a433d7bfa56d750907ba5cf74aed7"></a>
float&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structfaiss_1_1RandomGenerator.html#ac82a433d7bfa56d750907ba5cf74aed7">rand_float</a> ()</td></tr>
<tr class="memdesc:ac82a433d7bfa56d750907ba5cf74aed7"><td class="mdescLeft">&#160;</td><td class="mdescRight">between 0 and 1 <br/></td></tr>
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double&#160;</td><td class="memItemRight" valign="bottom"><b>rand_double</b> ()</td></tr>
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<tr class="memitem:a7633c373153f3b2824d2d99382ba20ab"><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a7633c373153f3b2824d2d99382ba20ab"></a>
&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structfaiss_1_1RandomGenerator.html#a7633c373153f3b2824d2d99382ba20ab">RandomGenerator</a> (long seed=1234)</td></tr>
<tr class="memdesc:a7633c373153f3b2824d2d99382ba20ab"><td class="mdescLeft">&#160;</td><td class="mdescRight">initialize <br/></td></tr>
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<tr class="memitem:a16c42957c159dbd910c15856a6b135de"><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a16c42957c159dbd910c15856a6b135de"></a>
&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structfaiss_1_1RandomGenerator.html#a16c42957c159dbd910c15856a6b135de">RandomGenerator</a> (const <a class="el" href="structfaiss_1_1RandomGenerator.html">RandomGenerator</a> &amp;other)</td></tr>
<tr class="memdesc:a16c42957c159dbd910c15856a6b135de"><td class="mdescLeft">&#160;</td><td class="mdescRight">default copy constructor messes up pointer in rand_data <br/></td></tr>
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<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<div class="textblock"><p>random generator that can be used in multithreaded contexts </p>

<p>Definition at line <a class="el" href="utils_8h_source.html#l00048">48</a> of file <a class="el" href="utils_8h_source.html">utils.h</a>.</p>
</div><h2 class="groupheader">Member Function Documentation</h2>
<a class="anchor" id="aa460b9bac2593cd1d71305e10ab51af6"></a>
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          <td class="memname">int faiss::RandomGenerator::rand_int </td>
          <td>(</td>
          <td class="paramtype">int&#160;</td>
          <td class="paramname"><em>max</em></td><td>)</td>
          <td></td>
        </tr>
      </table>
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<p>generate random number between 0 and max-1 </p>
<p>The definition of random functions depends on the architecture:</p>
<ul>
<li>for Linux, we rely on re-entrant functions (random_r). This provides good quality reproducible random sequences.</li>
<li>for Apple, we use rand_r. Apple is trying so hard to deprecate this function that it removed its definition form stdlib.h, so we re-declare it below. Fortunately, since it is deprecated, its prototype should not change much in the forerseeable future.</li>
</ul>
<p>Unfortunately, system designers are more concerned with making the most unpredictable random sequences for cryptographic use, when in scientific contexts what acutally matters is having reproducible squences in multi-threaded contexts. </p>

<p>Definition at line <a class="el" href="utils_8cpp_source.html#l00205">205</a> of file <a class="el" href="utils_8cpp_source.html">utils.cpp</a>.</p>

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<hr/>The documentation for this struct was generated from the following files:<ul>
<li>/data/users/matthijs/github_faiss/faiss/<a class="el" href="utils_8h_source.html">utils.h</a></li>
<li>/data/users/matthijs/github_faiss/faiss/<a class="el" href="utils_8cpp_source.html">utils.cpp</a></li>
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